Walmart has joined forces with Instacart to offer same-day delivery in four US markets as it seeks to rival Amazon’s rapid fulfilment proposition. 

Walmart products will be available to purchase via Instacart in San Francisco, Los Angeles and San Diego in California, as well as Tulsa in Oklahoma, as part of the initial trial. 

Shoppers will be able to purchase groceries, alcohol and home decor items to be delivered to their homes in as little as an hour. 

The proposition could be extended into more markets if it proves successful.

A Walmart spokeswoman said: “Customers love the value we bring with pick-up and delivery. They’ve turned to us during the pandemic to bring them their goods safely and easily.”

The move marks the latest salvo from Walmart in its ongoing fightback against Amazon, which currently offers free two-hour deliveries on groceries including items from Whole Foods, the grocer it purchased back in 2017.  

Walmart is ramping up its own fresh food delivery credentials in a bid to rival Amazon’s market-leading fulfilment options. Earlier this year it rolled out its Express Delivery service, which delivers items from stores to customers’ homes in less than two hours. 

The retailer has also launched its own ecommerce marketplace selling a host of third-party brands, and is working on its own subscription service, Walmart+, to rival Amazon Prime. 

The service will reportedly cost users $98 (£77) a year and include perks such as same-day delivery on grocery and general merchandise orders. The Walmart+ launch was previously expected in July but has been delayed. 

Walmart’s partnership with Instacart means it is the latest in a string of retailers to launch or expand its proposition on the app since the coronavirus pandemic hit the US at the beginning of March.

Instacart counts the likes of Kroger, Costco, Wegmans, Aldi, Loblaw and Publix among its growing stable of retail partners.